A significant and life-threatening heavy rainfall event will unfold over eastern Oklahoma and northwest Arkansas early this week.

A slow moving upper storm system will combine with well above average deep layer moisture and a focusing frontal boundary to produce excessive rainfall. The heavier rainfall will begin over eastern Oklahoma Monday evening and gradually shift east into far eastern Oklahoma and northwest Arkansas through Tuesday night and possibly into Wednesday before tapering off Wednesday night.

A flash flood watch will be in effect from 1 pm this afternoon through Wednesday morning

Widespread rainfall amounts from 4 to 8 inches are expected across a good portion of eastern Oklahoma and northwest Arkansas. Isolated areas could receive rainfall amounts between a foot and 15 inches. Widespread and potentially catastrophic areal flooding and river flooding would result should these amounts materialize.